Sound reproducing apparatus for endless band sound carriers



Nov. 21, 1939. G. FRIES I 2.18 1,l12

SOUND REPRODUCING APPARATUS FOR ENDLESS BAND SOUND CARRIERS Filed May 3, 1938 Patented Nov. 21, 1939 UNITED. STATES SOUND REPRODUCING APPARATUS ENDLESS BAND SOUND CARRIERS FOR Gustav Fries, Cologne, Germany, assignor to Tefi- Apparatebau I Dr. Daniel K.-G., Cologne, Germany Application May s, 1938, Serial No. 205,697 In Germany May 15, 1937 6 Claims. (Cl. 274-44) I An application was filed in Germany on May This invention relates to a sound reproducing apparatus for endless band sound record carriers of the kind having a plurality of sound recordings running parallel to one another in the 1ongitudinal direction of the carrier. Such apparatus allow of a very long sound reproduction with a single sound carrier so that frequently a plurality of independent sound recordings are prescut on one and the same sound record carrier. When it is considered that about one hundred sound lines at a distance from one another of .25 mm. can be produced on film-like sound hands by means of the needle sound method, it is understandable that the guiding of the sound carrier and particularly of the sound pick-up is of great importance. In order, with the above arrangement, to provide as simple as possible an operation of the apparatus, it is necessary to combine devices fulfilling diifgrent purposes as far as possible to a technical unit.

This problem is solved to a considerable extent by the present invention.. 1 2 According to the invention the sound pick-up which, .in such apparatus, can be adjusted, not by hand, but mechanically, to any desired sound track, is carried after the manner of aCardan joint and is limited in its direction of movement on one side by a 'stop coupled to a sound-lineindicating device and adjustable by hand.

In order that the invention may be fully understood, I shall now describe one embodiment thereof by way of example by reference to the accompanying diagrammatic drawing in which:

. Fig. 1 shows a reproducing device embodying the invention in perspective view, and

Fig. 2 shows the construction 'of the control sh'ait.

For driving the sound carrier an electric motor I is employed on the horizontal shaft 2 of which is arranged a drum 3. The endless film-like sound carrier 8 which is rolled into a coil is pressed, by pressure rollers! and 5, resiliently.

50 means of a spring 8 carrying a braking felt 9.

Guide strips Ill andll are connected to the pressure rollers 4 and 5 which strips guide the sound carrier out of the coil and back into the coil respectively, the latter being. arranged onsound carrier traverses lightly tensioned by' a plate or disc l3. The pressure roller 5 and the guide strip II are rotatable around the spindle 12 such that, on movement of the pressure roller away from the sound carrier, the guide strip II is simultaneously displaced away from the carrier. Studs l8 are provided on the strips 10 and H which, on the disengagement of the rollers 4 and 5, hook behind stationary pins 19.

The disc or plate 13 is driven by the motor I through the vertical shaft 14 by means of the member l5 and the pins l6 and I I provided on the sideplate l3. The sound carrier coil is wound in this manner so that the drum 3 shall not-have to draw it out of the coil, for which purpose a relatively large expenditure of force is necessary. The motor I is thus considerably relieved of load by means of this device so that a weak running or driving mechanism is entirely sufiicient for the uniform drive of a very long sound carrier of, for example, 100 m. length.

Owing to the'free coupling between the motor 'I and the plate 13, the latter can be drawn out from the apparatus together with the sound carrier coil, and the sound carrier, with the pressure rollers .4 and 5 disengaged, can be withdrawn from the drum 3 and be replaced by a new one.

All the parts of the apparatus are secured to a vertical wall 22 held by an angle bracket 2|.

The sound reproduction of the sound carrier is effected by means of an electric sound box 23 and needle 24- which, on account of the long period for which it has to be employed, preferably consists of a ground sapphire. The sound box 23 is carriedby an arm 36 which is universally mounted, that is to say; after the manner of a Garden joint, on a pin 25 secured to the wall 22. For the purpose of relieving the sound box 23 of load, a spiral spring 26 is employed which is coiled around a sleeve 21 which is rotatably arranged on the horizontal rotary shaft 25a of the'Cardan joint. A pin 29 is arranged on the sleeve 21, against which pin bears one end of the said spring and which can be adjusted by the lever 28 disposed on the sleeve 21. The other end of the spring is secured to a lever 3| by which the tension of the spring 26 can be varied. A pin 30 is arranged on the shaft 25a which pin engages or bears a ,ainst the one end of the spring and thus relieves the sound box 23 of load. If, on the other hand, the sound box 23 is raised, the spring 26 cannot follow the pin 30 as it is held fast by the pin 29. Consequently, in its raised position, the sound box 23 is no longer relieved of load by the spring so that the weight of the sound box 28 can come completely into action. This is of particular importance in connectionwith the mechanism to be described hereafter.

To the tone arm 36 is connected on angular rod 35 which carries a roller 34 at its free end. Under this roller is disposed an inclined plane 38 to the lower end of which is connected a stop 33a, and to the upper end of which is connected a horizontal rack 32. The rock 32 is in engagement with a pinion 31 which is provided on a vertical control shaft 38 provided at the upper end with a knob 39. A notched wheel 40 is, moreover, arranged on the control shaft 38 around the middle turn of which runs a draw cord 4| which carries a pointer 42 movable over a scale 43. The scale 43 is divided corresponding to the number of sound lines provided on the sound carrier, so that the position of the pointer 42 over the scale 43 indicates over which sound line the sound box has been adjusted.

The rack 32 is guided in a support 44 shown in dotted lines in Figure 1, which support is mounted rotatably'by means of a sleeve 41 on the control shaft 38, its rotation, however, be-

.ing prevented by a pin 45. An axial displacement between the sleeve 41 and the control rod 38 is prevented by a pin 48 arranged in the sleeve 41 and engaging a groove formed in the shaft 38.

The control shaft 38 can, besides its rotary movement, also carry out a rising movement H (Fig. 2). The support 44 of the rack 32 is thus moved also. For effecting the rising movement, two rotatable sleeves 50 and 52, which are inserted into time another, are provided at the upper end of the control shaft, the outerv sleeve formed in the outer sleeve 50, prevents this sleeve 1 from moving axially. On rotating by means of the knob. 48, to the left, the said shaft 38 is raised vertically. The inclined plane 33 is thereby also moved upwardly and takes with it the hitherto freely suspended roller 34 and thus lifts the sound box 23 from the sound carrier. At the same time, the roller 34 rolls downwardly on the inclined plane 33 until it is stopped by the stop 33a whereby the sound box is adjusted over the sound line, in the present example the twelfth,-as shown by the pointer 42 on the scale 43corresponding to the position of the stop 33a.

The control shaft 38 presses, in its lowest position, against a spring contact 51 which is included in the circuit of the driving motor. ating current flows from the network 58 .over the conduits 50 and the contact 51 to the motor. In the raised position of the control shaft 38, in which the sound box is also raised from the i sound carrier, the spring contact 51 is free (as The operat one side of the drum 3. Only when the said member 62 falls into a recess 64 formed on the edge of the sound carrier, is the contact 51 finally freed with the control shaft 38 in the raised position so that the driving motor will not receive any more current and the sound carrier thus is stopped. This arrangement has the following importance:

If a plurality of independent sound recordings 1 are present on a sound carrier, these will begin,

and care can easily be taken that this is the case on recording, always at the position of the recess 84. When the sound carrier is inserted in the apparatus, the sound box 23 is raised and the roller 34 runs down the inclined guide path 33 as far as the stop 33a. The "contact 51 remains open until the sound carrier is-inserted and the control shaft 38 presses it down. Then the control rod 60 springs resiliently over the contact 51. After a particular sound reproduction has been run off, the control shaft 38 is again rotated upwardly, the contact 51 being, however, maintained in its closed position by the rod 60. The sound carrier continues to run until the recess 64 comes into contact with the member 62. The latter falls temporarily into this recess 64, the contact 51 is broken and the circuit to the driving motor is interrupted. This position of the sound carrier thus rep-resents the beginning position for the next sound reproduction. If it is not desired to use the next, but some other part of the sound track, the pointer 42 is moved .to the required division on the scale by rotating the control shaft 38 by the knob 39. In this way, the stop 33a is moved simultaneously to the correct position. Then, by rotating the knob 49 to the right, the sound box is again set on the sound carrier. closed, the motor starts to run and the reproducing operation begins again.

In order to prevent the needle from being moved transversely over the sound carrier by hand during reproduction, a fixed pawl 66 is arranged at a height corresponding to that of the operating position in front of the notch engaging spring which engages the wheel 40 whereby the control shaft 38 is locked against rotation in the operating position.

As the sound box 23 carries out a circular movement about its vertical axis and the movement of the stop 33a is a linear one, the latter cannot be made flat but must be shaped according to a special curve, the form of which can be worked out either empirically or mathematically.

For the purpose of obtaining a simple curve, it

is advantageous to arrange the point: of rotation of the tone arm in a vertical plane passing through the longitudinal axis of the sound carrier.

I claim: 4

1. In a sound reproducing apparatus of the kind referred to, the subcombination of: a frame; a universally movable sound pick-up device carried by said frame; an adjustable stop device associated with said pick-up device for limiting movement of said pick-up device in one direction; a rotatable and axially displaceable control shaft operatively connected to said stop device and a sound-line indicating device operatively connected to said shaft; means for axially displacing said shaft; means operable on displacement of said shaft to move said stop device vertically and thereby also raise and lower said pick-up device; means for rotating said As the contact 51 is thus simultaneously shaft, and means operable on rotation of said shaft to move said stop device horizontally, whereby said pick-up device is adjusted horizon tally for the purpose specified.

2. In a sound reproducing apparatus of the kind referred to, the subcombination of: a frame; a universally mounted sound-pick-up device carried by said frame; a vertically movable support mounted in said frame; a horizontally movable rack carried in said support; an inclined surface, connected to said rack, said surface having a stop thereon; an arm, carrying a roller, connected to said pick-up device, said roller sliding on said surface and being adapted to engage said stop; means for vertically moving said support to raise said pick-up; means for horizontally moving said rack and consequently said stop to cause said pick-up to be displaced horizontally; a sound-line indicatg device associated with said rack moving means, ,and means operable on actuation of said rack-moving means to indicate the position to which said sound pick-up device has been adjusted.

3. In a sound reproducing apparatus of the kind referred to, the subcombination of: a frame; a universally mounted sound pick-up device on said frame; an adjustable stop device associated with said pick-up device; a rotatable and axially movable control shaft operatively connected to said stop device; a sound-line indicating device operatively connected to said control shaft; means for displacing said shaft axially, said means comprising an inner sleeve on said shaft, an outer sleeve surrounding said inner sleeve and a pin on said inner sleeve engaging a slot in said outer sleeve, manual,rotation of said outer sleeve thereby causing axial movement of said inner sleeve and said shaft, the arrangement being such that axial movement of said shaft causes vertical movement of said stop device and said pick-up device and rotation of said shaft causes horizontal displacement of said stop device and said pick-up device for the purpose specified.

4. In a sound reproducing apparatus of the kind referred to, the subconibination of a frame; an endless sound record carrier mounted in said frame; a universally movable tone-arm carrying a sound pick-up device mounted in said frame; an adjustable stop device associated with said tone-arm for limiting movement of said pickup device in one direction; an electric motor,for drivingthe endless sound record carrier; a contact included in the circuit of said motor; a rotatable and axially raisable control'shaft operatively connected to said stop device, said shaft in the normal position thereof engaging and closing said contact; means for vertically displacing said control shaft; means operable on displacement of said shaft to move said stop device vertically and move said pick-up device into and out of operative position with respect to said record carrier; means for rotating said shaft; means opkind referred to, the combination of: a frame;

a universally movable sound pick-up device mounted in said frame; an adjustable stop device associated with said sound pick-up for adjusting said device as required; a rotatable and axially displaceable control shaft carried by said frame for actuating said stop device; means for axially moving said shaft; an electric driving motor for moving the sound record carrier; a spring contact included in the circuit of said motor, said contact being engaged and closed by said shaft in the normal position thereof and disengaged therefrom when said shaft is displaced axially to disengage said pick-up device and a spring actuated rod adapted normally to maintain said contact closed and releasable therefrom in a predetermined position of the sound record carrier to allow said contact to open if said shaft is disengaged therefrom.

6. In a soun kind referred to, the sub-combination of: a frame; a versally mounted tone-arm, carrying a sound pick-up device in said frame; a horizontally and vertically adjustable inclined surface having a stop member thereon carried by said apparatus; an arm carrying a roller mounted on said tone-arm, said roller being associated with said inclined surface; means for moving said inclined surface vertically so as to raise and lower said sound pick-up; and means for moving said inclined surface horizontally so as to adjust said pick-up horizontally; and a sound-line indicating device coupled to said inclined surface for determining the position of adjustment of. said sound pick-up.

GUSTAV FRIES.

reproducing apparatus of the 

